Wo. 19. 



MONOGRAPH Y 



FAMILY UNIONIDil, 



OR NAIADES OF LAMARCK, 

 (FRESH WATER BIVALVE SHELLS,) 



NORTH AMERICA 



ILLUSTRATED BY FIGURES DRAWN ON STONE FROM NATURE. 



BY T. A. CONRAD, 



MEMBER OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA; 

 PALAEONTOLOGIST OF THE STATE OF NEW YORK, ETC. 



PHILADELPHIA: 



J. DOBSON, 108 CHESNUT STREET. 



BOSTON: PERKINS & NARVIK— PITTSBURGH: JOHN I. KAY & Co.- 



LONDON: O. RICH, No 12, RED LION SQUARE.— PARIS: ARTHUS 



BERTRAND, FILS, RUE HAUTEFEU1LLE No. VS.— HAMBURGH: 



PERTHES & BESSER, No. 22, AM JUNGFERNSTIEG. 



E. G. DORSEV, PRINTER. 



June, 1840. 



